Internal combustion engine



June 19, 1934. H. 1. A. DORNER INTERNAL COMBUSTION ENGINE Filed April 15, 1932 Patented June 19, 1934 1,963,578 INTERNAL COMBUSTION ENGINE Herman I. A. Dorner, Detroit,

Packard Motor Car Company,

corporation of Michigan Application April 13, 1932, Serial No. 605,001

7 Claims.

The present application, insofar as matter common to the two cases is concerned, is a continuation of my co-pending application, Serial No. 424,986, filed January 31, 1930.

This invention relates to internal combustion engines and more particularly to a method for charging engines with combustible mixtures.

With injection engines of the compression type in which the fuel is mixed in the combustion chambers, it is requisite that the air charges be in agitation and that the liquid fuel be introduced in a manner to intermingle with the agitated air during compression. I have found that certain types of fuel. sprays enable the fuel introduced under high pressure to penetrate rotating compressed air and at the same time spread over a relatively large area, within cer: tain limits of cylinder sizes into which they are introduced, with a comparatively uniform intermingling of the fuel with the air. When the size of the cylinder is beyond a certain limit, however, detonation becomes evident because the penetration and spread of the injected fuel relative to the air charge volume becomes less. As a result, the space in the cylinder occupied by-injected fuel under the usual high pressure is materially smaller than the remaining space, and the content is much richer relatively than that in the remaining space. Under such circumstances, the fuel charge in the smaller space will ignite first and the flame spreads so rapidly to the fuel charge in the remaining cylinder space as to cause substantially simultaneous combustion, thus causing detonation. As the cylinder size increases, the resulting detonation will likewise increase.

An object of this invention is to provide a method of charging cylinders of engines of the compression ignition type having relatively large 40 bores so that the resulting mixture is of a character substantially eliminating detonation when combustion takes place.

Another object of the invention is to provide a method of charging solid fuel injection en- 45 gines in a manner such that compressed rotating air will pick up the liquid fuel in spaces in the cylinder bores on opposite sides of the axis of air rotation.

Another object of the invention resides in 50 the method of charging a compression ignition engine in which the fuel is introduced into the compressed air in the cylinder in two concentrlc jets, one of which penetrates further into the cylinder than the other. 4 55 Other objects of the invention will appear TES PATENT OFFICE Mich., assignor to Detroit, Mich., a

from the following description taken in connection with the drawin and in which:

of this specification,

which forms a part Fig. 1 is a fragmentary vertical sectional view of a fuel injection device attached to a fragment of an engine cylinder;

Fig. 2 is. a horizontal sectional view through the cylinder substantially in a plane with the injection device;

Fig. 3 is a top plane view of an engine cylinder having an injection device associated therewith;

Fig. 4 is an enlarge (1 fragmentary sectional view of the injection end of the fuel nozzle associated with the cylinder.

Referring to the drawing by characters of reference, 10 is a cylinder of an internal combustion engine, preferably of the Diesel type, in

which the piston 11 is arranged to be reciprocated. The cylinder head is provided with a neck 12 through which a Venturi passage 13 extends to connect the interior of the cylinder with the atmosphere and a suitable valve mechanism is associated with the inner end of the passage exhaust.

air and the escape of serves as both the air inlet and the exhaust outlet and is formed and related with the cylinder in Patent Reissue scribed in my 22, 1929. enters the combustion The passage is the manner de- No. 1,775 of April so arranged that air chamber, which in this instance is the cylinder, tangentially of the inner wall and at an angle to the axis so that air drawn into the chamber by the piston will be caused to rotate substantially as a mass' or column in a direction shown by the arrows in h Fig. 2, and such rotation continues during the compression stroke.

The engine illustrated is of the four stroke cycle type, air being drawn into the cylinder during the suction stroke of the piston, the rotating air being compressed in the cylinder during a portion of injected into the pression stroke the compression stroke, fuel being air near the end of the comand explosion taking place at the extreme end of the compression stroke and duringthe power stroke,

the exhaust stroke.

place during and exhaust taking The cylinder illustrated is of a relatively large bore type and in order to introduce device which consists liquid fuel into the air I provide an injection tion 14 and a pump section 15.

The pump section of the injection device includes an outer casing riedabarreltlinw 16 within which is carhich the plunger 18 reciprocates. A fuel inlet manifold communicates with a housing 19 which surrounds the casing and is secured and wedged in leak-proof relation by a nut 20, there being a plurality of radial inlet ports 21 extending through the easing and the barrel establishing communication between the housing and the interior of the barrel while uncovered by the plunger. Spring pressed check valves 22 are provided in the upper end of the casing to prevent return flow of liquid fuel from the nozzle section to the pump section. Suitable mechanism (not shown) is provided for moving the pump plunger 18 toward the nozzle to trap fuel beyond the ports 21 and to force a portion thereof through the nozzle, and a coil spring 23 is associated with the plunger to normally maintain the same in a relation in the barrel such that it uncovers the ports 21.

The nozzle is carried by a casing 24 which is screwed into an end of the pump casing and includes a transversely extending portion 25, the latter portion having a flange 26 which is secured to a boss on the cylinder wall by bolts 27. A nozzle housing 28 extends through the attached end of the casing 25 and projects through an aperture in the cylinder wall, so that its end is adjacent the inner surface of the cylinder wall. A plug 29 is wedged into the outer end of the casing and is secured axially by the cap 30, the set screw 31 preventing rotation thereof. The nozzle housing screws into the plug, and the nozzle housing, plug and casing are formed to provide a fuel passage which establishes communication between the pump casing and the interior of the cylinder. It will be understood that the housing 19 is connected in a suitable manner with the source of liquid fuel under low pressure so that when the ports 21 are uncovered, all the space in the barrel'will be filled with liquid fuel. The viscosity of the fuel is sufliciently high to substantially prevent any leakage of fuel from the discharge end of the nozzle during the intervals between injections.

In order to control the fuel flow through the nozzle, I provide a valve 32 which is arranged within the passage through the nozzle housing and in a portion of the plug. A stop member 33 is arranged to limit the movement of the valve rod in a direction exteriorly of the engine cylinder, which is the closing movement, while the coil spring 34 is arranged to resist opening movement of the valve member when the fuel in the device is placed under pressure by the pump plunger and to return the valve against the stop member when the pressure created by the plunger is discontinued: The port at the outlet end 35 of the passage in the nozzle housing is preferably conical in shape and tapers out toward the interior of the cylinder, while the valve head 36 is curved outwardly from the stem 34 and is arcuate at its end so that a circular edge 37 approaches the wall of the conical outlet passage in the discharge end of the housing 28. I

The stop member 33 is arranged so that this circular valve edge will not quite engage the housing when in retracted telescoping relation therewith, and consequently the nozzle will always remain slightly open. Fuel will be projected exteriorly of the circular valve edge 3'7 and will issue from the nozzle in conical form due to this arrangement of the valve and the co-operative housing outlet. Upon the injection or pressure stroke of the plunger 18, the fuel inlet ports 21 will be closed and fuel will be trapped in the device and discharged from the nozzle in accordance with the plunger movement after closing the passages. By regulating the length of the plunger stroke after closing the ports 21, the volume of fuel injected from the device can be regulated.

The fuel injections, with the device so far described, are of a character to provide an intermingling with the rotating compressed air in cylinders of a limited diameter such that distribution is uniform enough to eliminate detonation. It will be understood that a very few drops of liquid fuel are injected into the cylinder to constitute each charge and that the plunger 18 produces a pressure, due to the resistance of the valve, which is very high and therefore fine atomization will take place. This type of atomization is necessary for the proper commingling with air in the cylinders when the mixture must become gasified in the brief interval of time occuring between introductions near the end of the compression stroke and the explosion approximately at the top of the compression stroke, but with such type of atomization there is a limit to its penetration of the rotating air and with cylinders of the smaller bore such penetration is sufficient for the injected charges to reach the axis of rotation of the air charges so that proper commingling takes place, but when the cylinders are of a larger bore, then the penetration falls short of the axis of the rotation of the air charges and detonation takes place as the space in the cylinder which fuel under injection pressure occupies is proportionately less than the remaining space and detonation takes place due to the rapid spread of flame from the more highly volatile space to the larger remaining space wherein, under such circumstances, the ignition will be substantially instantaneous.

Therefore, with cylinders of a relatively large bore, I propose to increase the space occupied by the fuel in the cylinder under injection pressure by providing a valve head 36 with an outlet passage 38 into which liquid fuel flows from the nozzlehousing through radial passages 39. The passage 38 preferably extends axially through the end of the valve head and is of a diameter such that a substantial volume of'fuel passing therethrough during injection issues as a stream or jet which will penetrate past the axis of the rotating air charge column or mass in the cylinder. With this arrangement of fuel outlets, I provide for the issuance of a pair of concentric jets of fuel, the outer one of which is conical and finely divided and the inner of which will project in a stream considerably further than the conical jet will project because of the difference in atomization and volume. Due to the very small size of the nozzle outlets and the viscosity of the fuel there will be substantially no leakage therefrom.

The spread of the fuel in the rotating compressed air into the two areas, resulting from the nozzle outlet design and the pressure developed by the plunger, is illustrated in Fig. 2 of the drawing. The area A is occupied by the fuel issuing from around the valve head, while the space B is occupied by the fuel issuing from the valve passage 38. The fuel in the space B increases the uniform distribution of the fuel in the compressed air and results in a more gradual flame propagation throughout the combustion space of the cylinder. I preferably provide the opening 38 so that pressure against fuel in the nozzle will force a jet therethrough considerably 7 past the axis of the cylinder with which the device is associated and thus the compressed air rotating from the cylinder will pick up the fuel on opposite sides of the axis of the cylinder and will thus provide two fuel enriched spaces in the cylinder as indicated at A and B rather than in the one space A which would result if the outlet passage 38 were not provided.

It will be seen that this method of charging a cylinder assists in commingling fuel with air charges in a uniform manner, that its provides two enriched spaces so that flame propagation will be more gradual and, as a result, efliciency of an engine of the compression ignition type having cylinders of a relatively large bore is thus greatly increased without increasing the size of the injection device over that used with a smaller bore cylinder and without the use of two injecting devices.

Although the invention has been described in connection vith a specific embodiment, the prin ciples involved are susceptible of numerous other applications which will readily occur to persons skilled in the art. The invention is therefore to be limited only as indicated by the scope of the appended claims.

What I claim is:

l. A method of forming combustible mixtures in internal combustion engine cylinders comprising introducing air charges into the combustion chambers in a manner causing rotation thereof as masses, compressing the air charges rotating in the chambers, introducing a fine conical spray of liquid fuel radially into the rotating air charges while being compressed under pressure such that it penetrates short of the axis, and introducing a second spray of liquid fuel radially into the cylinder chamber at a pressure such that it penetrates beyond the axis of the rotating air charges while being compressed.

2. A method of forming combustible mixtures in internal combustion engine cylinders comprising introducing air charges into the combustion chambers in a manner causing rotation thereof as masses, compressing the air charges rotating in the chambers, simultaneously introducing two sprays of liquid fuel radially into the rotating air charges while being compressed, said sprays having a different degree of atomization and penetrating different distances into the rotating air.

3. A method of forming combustible mixtures in internal combustion engine combustion chambers comprising introducing air charges into the chambers in a manner causing rotation thereof as masses, compressing the air charges rotating in the chambers, and introducing by pressure concentric sprays of liquid fuel radially into the rotating air charges while being'compressed, one of said sprays being projected a much greater distance than the other into the rotating air.

4. A method of forming combustible mixtures in internal combustion engine cylinders comprising introducing air charges into the combustion chambers in a manner causing rotation thereof as masses, compressing the air charges rotating in the combustion chambers, and introducing concentric sprays of liquid fuel in different conditions of atomization radially into the rotating air charges different distances.

5. The method of forming combustible mixtures in an internal combustion engine cylinder comprising introducing into the cylinder charges of air in a manner promoting rotation therein as amass, compressing the rotating air charge masses in the cylinder,-and introducing two concentric jets of liquid fuel in different degrees of atomization radially into the rotating masses of compressed air under a force such that the coarser jet penetrates beyond the axis of the rotating mass and the finer jet penetrates the mass a shorter distance than the coarser jet.

6. The method of forming combustiblemixtures in an internal combustion engine cylinder comprising introducing charges of air into the cylinder in a manner promoting rotation thereof as masses, compressing the air masses rotating in the cylinder, and introducing two concentric jets of liquid fuel radially into the rotating masses of compressed air under a force such that one jet penetrates beyond the axis of the rotating mass and the other jet penetrates the mass short of the axis of rotation.

7. Themethod of forming combustible mixtures in an internal combustion engine cylinder comprising introducing charges of air into the cylinder in a manner promoting rotation thereof as masses, compressing the rotating air charge masses in the cylinder, and introducing concentric streams of liquid fuel radially into the rotating air masses in the cylinder different distances with=one stream terminating short ofand the other stream penetrating beyond the axis of air rotation, such introduction of the fuel forming two highly fuelized air areas diametric of the axis of air rotation.

HERMANN I. A. DORNER. 

